Christy, that’s not actually true, in that the term “microevolution” dates way back to the twenties, and I’ve seen it used in quite a number of papers with no anti-evolutionary influences. I’ve even seen it in a university population genetics primer, in which “macroevolution” is said to be the business of palaeontologists rather than pop. geneticists (which was, it seemed to me, rather an abdication of responsibility).
It is, however, a useful distinction for discussing whether population genetics answers all the questions at the larger scale, which has certainly been questioned on many grounds, and at many times - hence its original coining. From Stamford Dictionary of Philosophy article:
Implicit in this definition [change in gene frequencies] is the idea that evolutionary phenomena such as speciation, adaptive radiation, diversification, as well as phenotypic evolution, can ultimately be reduced to gene frequency change. But do we really know this to be true? Many biologists, particularly ‘whole organism’ biologists, are not convinced, and thus reject both the population-genetic definition of evolution and the primacy traditionally accorded to population genetics within evolutionary biology (Pigliucci 2008)…
…Authors such as Gould (2002) and Eldredge (1989), for example, have argued persuasively that macro-evolutionary phenomena are governed by autonomous dynamics, irreducible to a microevolutionary basis. Philosophical discussions of this issue include Sterelny (1996), Grantham (1995) and Okasha (2006).
I don’t think any of those sources are creationists.
As to the “change of gene frequency” definition, when I cited it a year or two ago Josh Swamidass insisted that the preferred scientific definition of evolution was “common descent”. Disbelieving him I checked around various sites, and found he was right in many cases - check this from NCSE (and this from Ted Davis).